Seems I should expect to pay somewhere between 300-400 baht?
I guess it would depend on the exact calling service(s) used for Int'l LD, local calls, and getting the exact data plan which meets your requirements.
Two weeks means you really have to go for a 30 day plan, or two, one-week plans, which would require extra management and subscription.
Maybe closer to 600-800 baht all in?
You could get the DTAC Happy Tourist Light User SIM/plan for 429 baht, then add more value to cover your calls. Local calls are 1 baht/min, using 004 would be 2.5 baht/min to USA and 4 baht/min to Israel. All exclusive of 7% VAT.
http://www.dtac.co.th/en/prepaid/pro...-packages.html
Or you could try to get a SIM, add value, then subscribe to the appropriate data plan.
1.5 GB/30 days, 199 baht, for example:
http://www.dtac.co.th/en/prepaid/pro...t-package.html
At the airport I think they'll speak English, but the lines can be long there. You can buy a SIM and add value pretty much anywhere.
Just found this 15-day, 599 baht Touristy SIM:
http://store.dtac.co.th/en/happytouristsim
http://www.dtac.co.th/cms-storage/ha...urist_sim.jpeg